Protected cooler



Sept. 16, 1952 R. w. JENSEN 2,610,831

PROTECTED COOLER Filed Sept. 24, 1946 :s Sheet s-Sheet 1 INVENTOR RAYMOND W. JENSEN m- 6 1 5 R. w. JENSEN 2,610,831

PROTECTED COOLER Filed Sept. 24. 1946 3 Sheets-Sheet 3 5 INVENTOR RAYMOND w. JENSEN ATTORNEY Patented Sept. 16, 1952 iUN-ITE'D #STAT-ES PATENT l 2,610,831 I I I yPROT-ECTED GQOL'ER ..:R l!1nondjW. Jensem Los AngeleslGalifii-assignor to The Garrett CorporatiomLos'Angeles, Callie :acorporation of California r I Application September 24, 1946, Serial'N0. 699,083

, 24L Claims.

This inventionrelates 110 heat exchangers, .being a continuation in part oizapplicanfls copending application -for' a Protected Cooler SerialgNo. :-521,'5i0, filed February :18, 19.44,-now abandoned, =-and has-particular reference to coolers for ,the "oil used in 'lubrieating internal combustion engines, especially of the typeznsed in aeronautical apparatus, wherein conditions of'heatzando icold, and vobstruction -and impedance \ariseand must be met to provide the most satisiactory statefor theefficientoperationof the engine under all con- "ditions oftemperaturmaltitude and the. compositionof the oil.

The invention therefore relates also to ameans in combination with a cooler for governing the conditions that contribute most effectuallyto the economic and efficientoperation ioi. combustion engines. r r Heat exchangersoroil coolers are employed to maintain the oil-of internal combustion engines in 'propereonditiQmof fluidity and viscosity. It happens not infrequently that sudden and/or 1 severe variations of temperature" from a, normal 'or ideal working temperature .iproduces either partial or complete impedance to the circuit of the'oil through the coolemwith a resultant :pressure build-up that, unless relieved, would cause a rupture of the cooler-units or an irreparable injury to'thecoolen I'n-high altitudesaatotal or 'partial functional inhibition of the cooler would -resultin serious danger-to the pilot and occupants "of "the plane. T preventtheseioccurrences, the "oil which' cannot-travel: through the cooler; because of obstructionsthereim is caused to circum- "vent the cooler and to return to the I engine. the circumvented-travel continuing until the condition-of impedance (or-obstruction, which m-ayarise from a'number'of causes is eliminated.

To obviate the enumerated difiicul'ties, the present device isg designedgand it is an object of cooler, a *valve and valve mechanism by which theflowof oil is controlled automatically-- and consistentlywhether tliroughi the cooler, its muff,

"or in circ'umve'ntionof-them, to theend that oil L isalwaysand under all conditions removed from 1 and returned to the engine. a

It is anotherobject of theinventionto provide a simple valve which is'in'iluenced by pressure to enable the oil to bypass the cooler, in case of 'obstruetion oi impedance therein, and by heat to reroute the travel of oil through the heatexchanger or 'coole-r when the temperature of theoil rises aiidlthe-restrictionin the cooler is removed.

Ibis-a; further obj eet of the invention to provide (Gl.\257--2) I a valvehassembly -whlchs,lsxs.imple, substantialand zcompact andinwhichthe valve may be shottened -.and:.made lighter-than waives-presently use,d,efor

the purpose of ;c0nservlng-space, withoutimpair- 5 iingtheefficiencyzof thewvalve.

ltiis :a further :object-.of.;the invention taprovide a- ,valvesassemblyi of :the. nature :set forth in which the. valve jmayiber-made: :asiglight. and as smallraspossible, consistent with safetygandssurety. iofinoperationeandin which :allrparts .of the assembly are readily accessible.

..It is.;.a .;further object. ofrzthenmvention to mevidea valve :whiohis readily a djnstable:to;fune- .tion in a1wiide rangeof prcssuresand tempera- .tures,-,an.d which;..is.interrchangeable with valves having similar :pnrmses; inviews and especially with the type knownas fSYlPhoni It. is" a-still. fuhthermbiect :ofthejnwnflqnto provide theidevice with, meahsrto-;. rotect the/.011

cooler a ainstsursereactionorbackpr ssures- .In .the drawingsr'wliiohqareillustrative of a form'otembodimentof theinvention,

Fig; 1,;is a;sectional,i.:elevationa1.view;showing my invention.

' fig.;2,.is;a section;taken online: 2*: .of Fig. i.

,Fig.:-3;;is:.a sectiontaken Qnthe line 373 of Fig.1.

jig. Q4 is la-reduced,elevational view partly: secitioned, illustrating the .oil flows.

Fig.,5 is: an :enlarged :sectional view showing a A fiow Vcontrolrvalve ofimypinvention iii-normal posi- .etion.

.Fig.:6 isannenlargedsectiona view showing the valve ;:in 1' another ;position as :as'sumed. when :the

,35 :oil'fiowingthrough; the devieejiisutoo cold.

v 140' fie'd'form of valve. v the" invention to 'provide lncombination with a plates :l3:extendingzalternately from oneside to gneanxthe' opposite side ;of th exchanger ll to cause the oiito travel in :a zigzag course; as indicated'by'thedotted linesatin Fig; 4. Amufior "jacket l4. encircles., the:core 1 l I and OlLentering -thereinat the-top passes through the opening w in the bottom to the core eventually leaving the core, under normal conditions, through an outlet port ||i in the top of the exchanger l0, after giving up a substantial part of its heat while passing through the same. When, for any reason, the oil is prevented from passing through the core II, it continues its circuit through the muff I4, around the core, eventually leaving the muff, circumventing the heat exchanger H), in the manner and by the means hereinafter described.

It will be observed that the cooler HI and the valve assembly act in cooperation to maintain the hot oil from the engine in proper condition of heat; to remove obstructing or constricting deposits which have accumulated on the outs.de of the core tubes and to reduce the viscous character of the oil by increasing the heat of the oil; and to prevent injury to the cooler by eliminating pressure build-up when the cooler obstructs the free flow of oil therethrough.

A fitting I1 is associated with the heat exchanger I0, and has communication with the muif |4 through an opening or port |8 whereby oil is caused to traverse the muff, from which it enters the core ll of the heat exchanger l through the aforementioned opening l in the bottom of the core, as explained hereinafter.

The fitting ll extends through the muff l4 and has passageways I9, 20, and 2|, the passageways l9 and being in communication with the muff l4 and the passageway 2| bein in communication directly with the core H of the heat exchanger, whereby the oil, under normal conditions, is caused to traverse the mud H to enter the core through the opening l5 and to leave the core through the outlet port IS in the top of the heat exchanger. On the fitting I! is mounted a housing 22 formed with a chamber 23, having a passageway or port 24 which communicates with the passageway IS in the fitting I1. Oil from the engine is arranged to enter said chamber 23 and to pass therefrom through the ports 24 and I9, respectively in the chamber 23 and fitting 1, to the muif l4. In the event that the oil is obstructed in its flow through the chamber 23, it is caused to be diverted through a bypass 25 in said housing 22, and a means for accomplishing this diversion may comprise a double valve, generally indicated at 26, and including a valve member 2'! on one end of a stem 28. The valve member 21 is arranged for seating in the opening 24 in said chamber 23. On the other end of said stem 28 is a cylindrical, hollow valve member 29, which is arranged for seating in an opening or passageway 3!! in a wall 3| which separates the chamber 23 from the bypass 25. This cylindrical valve member 29 is held normally seated in the passageway 30, by a spring 32, contained within the cylindrical portion of the valve member 29, and is held in condition of compression by a cap 33 secured to the housing 22. During the normal flow of the oil from the engine, the cylindrical valve member 29 is seated and the companion valve 21 is unseated, thus enabling the oil to flow freely from the chamber 23, through the port 24 to the mufi I4. When any obstruction occurs to impede the free flow of oil, the pressure resulting from the obstruction lifts the cylindrical valve member 29 from its seat, thereby establishing communication between the chamber 23 and the bypass 25. Simultaneously, the valve member 21 is caused to seat in the opening 24, thereby closing communication between the chamber 23 and muff l4, and causing all the oil to pass from the chamber 23 to th bypass 25, and from there through any desirable course to the engine. The traverse of the oil in this manner continues until the restriction or impedance responsible for the pressure build-up is removed.

The housing 22 has a chamber 3'! which is in communication with the aforenamed passageway 20 in the fitting I1, and through said passageway 20 with the muff l4, and which is referred to hereinafter as a pressure chamber. The chamber 31 has an outlet opening or port 38 in a wall 38 thereof which is disposed at an angle to the horizontal. The said port 38 is arranged to be closed and opened under various conditions during the operation of the engine, as explained hereinafter, by a valve member 40, which constitutes a part of a composite valve structure, generally indicated at 4|. The valve structure 4|, is located in a valve chamber 35 which is connected with the passageway 2| through a port 34 controlled by a check valve, indicated generally at 36, and comprising a seat member 36a having an opening 382) therein, and a movable valve member or disc 360 which is pivoted on a pin 36d in ears 36c integral with the seat 36a. The valve disc 36c is urged in the seating direction by a light spring 36f and closes the opening 36b against back flow of oil toward the core.

The valve structure 4| includes said valve member 40 and a hollow stem 42, and an opening 43, which is diametrically smaller than the hollow or bore of the stem 42. The opening 43 is normally closed by a ball valve 43a yieldingly held on its seat by a spring 43b which is retained in position by any suitable means which, as shown, comprises a pin 43c extending transversely through the stem 42. At its other end, the valve stem 42 is secured to a piston 44, which is operably disposed within a cap 45 secured in the housing 22 at substantially an angle corresponding to the angle 01' the wall 39 in the pressure chamber 31. The longitudinal axis of the stem 42 thus lies at substantially right angles to the transverse plane of the valve member 40 and the cap 45. The angular positioning of the valve member 40 and its complementary parts enables the unitary valve structure to be reduced in size and weight, to be compacted within the smallest possible dimension without sacrifice of strength, and to be readily accessible. The cap 45 provides a chamber 46 in which the said piston 44 operates as presently explained. The piston 44 is cylindrical and has a transverse wall 41 which is provided with openings 48 which connect said chamber 46 with a recess 49. In the recess 49 is arranged to operate a valve 5|, which is normally urged therein or thereagainst by a spring 52, on the stem 42 and supported on the stem by a snap ring 53 or any other device.

The valve 5| is slidable longitudinally of the stem 42 and functions as a relief valve in conjunction with openings 48 to relieve sudden increases in pressure in chamber 46 which may occur when the oil pressures in chamber 31 suddenly exceed the resistance of spring 54. This latter spring is contained within chamber 46 and, being compressed between said cylindrical piston 44 and cap 45, serves to normally urge valve member 40 onto its seat in port 38. The functions of valve 5| will be more clearly explained when discussingthe operation of the entire valve assembly.

At a point intermediate its ends the valve stem 42 has a port 55, which is arranged to be opened and closed by a sleeve or other member 56,

-rotativelyassociated-withsaidvalve =stem '42; and provided with a 'slo't 'i'l. 1 Rotative ,mot-ionis imparted-tosaid sleeve 56: through a bl-metallic thermostatic coil 58 connected at-one endto said sleeve 58and at the'other end to-asupport 59, which, in turn, is fastened to said valvemember 40. I Under theinfiuence of heat orxcold .+that is,

hot oil-or-cold oil-'and the resultant expansion and contraction of the thermostatic:coil 58,. the

sleeve 56 is rotated about the stem '42 .to move the slot '5'l therein" in register or out of register with the port 55', in 'theustem" 42. v

'Itwill be noted that theport 55 in therstem 4 2 is sufliciently large to enable a greaterquantity of oil to ilow out therethrough than team enterthrough the narrower or: smaller port: 43 in the endof the stem 42. lSincethe hollow stem is in" constant communication with the-L'chamber 46, theresult -of such major flow of oil:through the'port 55 is' to drainaportionof the roil from the chamber 46,-andzthus to create .a:low;pres

sure therein. The-piston 44 may "then lbermoved in the :chamber: 46: against "the resistance of the spring 54,. and :concurrently T-then valve: member 40 unseated, the: movement of the composite valve structure 4 l in. this: manner being effectuated :by

' 5 I will openzxand :relieverthe ipressurepithuszen- ;abling the-valve 40; toJopen.

,The normal 1 position :of complement l'iS indicatedzsubstantially in Fig. 5, in zwhichiposition ,the :valve I 40is closed; and: the 5105751,,1171' thezsleevex5li:is-out of register with theport 55 inthe stem1 42. By/normal position,

I'meanthat position of the parts produced when I the 011, is .heated and traveling freelyufromwthe engine;through the heat exchanger and-:themback againto the engine.

iAt; the: outset .of operation, of: the 2 engine ithe oil risncold. It passesgithrough: thegchamber-in to, the :muff M, from whicha;portion-ofr1the,oil is; diverted-to; circuit; through the: core i l;.of-:.the heataexchanger; which itrleaves through theoutlet opening lfifto. enter :thevalve chamber;35. :From

. the valve chamber. 35, ,the, oil:passesutoxthe bypass chamber and thenv to; the; engine, ;directly;.or

, indirectly.

gFrequently if- -not-commonly, the oil in passingthrough: the :heat exchangencongealszenaccount of the cold therein, and isgthus' impeded in its free flow. This resultstina pressure buildup, whichcauses a portion of the oil in the mufl to 7 continue ritswtravel, therein iito the pressure chamber 31,; ands another; portion of the oil :to

pass out of 'thezheat. exchanger through the port 56 therein into the. valve chamber 35 and thence into the: bypass '25 for returnto theengine. The cold ',oi l,, influencing the thermostatic ;:coil #58,

imparts-a rotative movement to .thesleevet 56 and registers theopenin 51;therein with the .port155 in the stem r 42. simultaneouslyrthe: entire valve structure 4 I ismovediby thepressurein the pres- .sure chamber:311and-thevalvemember '40 unseated, permitting inthis: manner the flow of oil to; occur through the valve chamber-35 and the pressure chamber 31 .to. the'bypa-ss'i5ifrom which it travels back-to the engine; '-'When the thermostatic coil. operatesthesleeve '56 to cause "the registry of the .pOItSI51 andl55 in, the sleeve and stem respectively, arpart of the oil enters'the the valve'--40.1and., its

stemvflxthroughithe port :43. therein and: passes "through-the'openingorport 55 to commin lewith the oil travelingzithrough. the valve, chamber 35. Slncegasstated, the outletiport" 55 islarger :than the entry-port 43, more oil will. beoallowed to flow -from the. stemi thanenters :it and in thisamanner oil-willbe drained from. the chamber 45,- which twill then be: substantially pressure ,free. Thereby; thevalvemexriben" may be unseated, as. and for the'purposes related, as the. entire vvalvestructure" 4| is moved by pressure :exerted. against the valve member 40 from the-pressure chamber :31.

iwhenthe thermostatic coil .58 becomes heated 'by the oilwsurroundinggit; :the, sleeve "valve 56 closes the port 355,x:whereupon the oilwill pass through the stem-:42 :to .the chamber '4 6; and" the pressure therein twill become :equalized to ;the :pressureqagainst. thetvalve-member 40.

The, springi- 54, therefore, inrthe chamber. 46, will :move the :valve structure 4 I. and cause the "valvamemberufll' to seateaszishownhin Fig. 5,. thus "shutting; oifrzthe flowcof oil from the: muff.;,and

'forcing': the now Lheatedoil/.to circuit through xtheaheat'exchanger. V

Sudden. surges of athe, .o'il'through the system, and especially :through theiheat exchangercwhich would subjectlthe core of, ;the.:exchanger to: undue pressureaandtha'danger ,of: ruptureor otherrdamages will iorce arsuch pressure build-up to be exerted-throughztherpressure chamberiil against tthe valve memberwiogwhich is thereby; unseated, as, shown win 7,; permittingzmhe, oil :to pass tfreely Iromzsaidlbypass:chamber: 31 through the valve ,chambern; .p'lIhe unseating ofx-ithe-valve 4loccursagainstthe pressureof. oil that-has been 'Ltrappedz-inthe chamberdfi. "';This;pressure.isrelieved byithe oil passingthroughthepassageways KABjIITtheJGYIiIlGIiCaI piston 44,. and, unseating the relief ;'va1ve;5l,e'escapingziinto the valve cham- ,ber:'35.

JShould". there: beeazzsurge of, oilisuch .as would :cause back pressure in --.the chamber 35, the check valve; 35c will. close; and, should I the port :155 beyopenxat;thishtimemcheck valve 43a will prevent :this pressure .;;f-rom being transmitted :through the opening-1l3zto thenchamber and massages. 10f .zthes; cooler 11 anteriorto said cham- .ber ;3.'|. Briefly'lirev-iewing ith-e operation .of the :valve. ;unit, it :wilL-znow be, apparent that in, the

temperature range of normal operation, the .valve: LWi11 beJlhQ1dl' closed by-.- a combination of :fluid IPIGSSUIQ' in. the; chamber 46 (substan- .tially balancing theifiuid pressure at the by ass eoutlet120); plus the pressureofthe spring 54, so

zzthatithenet effective- ,pressure of; the valve 40 :against. its :seatgis that :of :the. spring :54. ,The iflllld pressure in 1. the :chamber 46 (is equivalent to: the pressure at :ithe bypassoutlet 12 0 because oizzithe 2 continuous "bleed :of; oil :from the: bypass ,;outleti:20' through .il-theghollow stem 42 into ,the chamber 146, :the outletuport being closed by 'the thermostatically. controlled zpilot'zvalve sleeve 56. "On the other. hand,-xwhen v:the temperature in the cooler -is substantially below the .normal operating range,-':the -oil bleeding into the valve stemthrough the' port 43-, instead of building .up pressure -in the chamber -46, will all escape "through theport' '55 in the valve stem, which, .being ofgreater-area than the bleed opening "43,--will permi-t the pressure in the chamber 'toxbereleased. This'will permit the differential in pressure between the higherppressure in the bypass outlet 20 and the lower'pressure in the core outlet 2| (caused by=the resistance to-flow through the core) to become efiective to move the valve 46 and piston 44 against the resistance of the spring 54 and permit the oil, or a portion thereof, to bypass through the muff I4 and escape through the bypass 25. However, when the pressure in the chamber 31 exceeds a predetermined maximum (either because of congealment or as a result of sudden pressure surges) the valve 40 will yield, even though the escape port 55 in the valve stem is closed and the valve accordingly subjected to full pressure in the chamber 46. The yielding of the valve 40 in this case is permitted by the release of excess pressure from the chamber 46 past the relief valve 5|. Thus, the resistance of the spring 52 acting against the relief valve 5| determines the maximum pressure beyond which the valve 45 will yield in any event.

Figs. 8, 9 and 10 represent a modified form of valve. The valve member 40, operating to open and close communication between the chamber 31 and the valve chamber 35, is on one end 01' a hollow stem 60. The other end 6| of the stem 60 extends through and is operable rela tive to a piston 62, which is movably disposed within the chamber 46, formed by the cap 45 secured in the housing 22. The piston 62 is normally held against a stop 63 which limits the movement of the piston 62 outwardly in the cap 45 by a spring 64. The movement of said piston 62 relatively to the hollow stem is limited by a snap ring or other stop device 65. A spring 66 about the hollow stem 66 and interposed between the valve member 40 and piston 62 serves to hold the piston 62 against the snap ring 65.

The stem 60 has an entry port 66' which is in 1 communication with the hollow of the stem and in which port 66 a ball valve 6'! is held normally seated by a spring 68, which is retained in position by any desired means, as, for instance, a pin 69 extending transversely through said stem. The stem 60, intermediate its length, has an outlet opening 10, of a diameter or size larger than the inlet or entry port 66, for the purpose of permitting more oil to flow from the hollow stem than can enter it through the entry port 66. In this manner oil in the chamber 46 may flow out of the stem concurrently with the incoming oil, thus reducing the pressure therein and permitting valve 43 to unseat as shown in Figure 9.

It will be noted that the hollow of the stem 60 is in constant communication with said chamber 46. Encircling the hollow stem 60 is a thermostatic helix H, at one end fastened to said stem, and at the other end connected to a sleeve 12 having a cam edge 13 that is designed to cooperate with the port 19 in the stem to open or close the same in response to the expensive and contractive action of the thermostatic helix H. Under normal conditions-that is, when the coil is heated and freely circulating-the parts of the valve are substantially in the position illustrated in Fig. 8. When the oil is cold and under pressure, due to restricted flow through the heat exchanger, the pressure in the chamber 31 tends to unseat the valve 40. The cold oil acting upon the thermostatic H, rotates the sleeve 12 and causes the cam edge 13 to uncover the port 10 in the stem 60, which, as stated, is in communication with the chamber 46 and thus releases the oil therefrom. The pressure against the valve 40 may then operate to unseat the valve.

In the event of a high pressure surge through the muff, produced, for instance, by a sudden impedance to the free flow or oil through the heat exchanger, the entire valve assembly described acts as a relief valve. The piston 62 in this instance is held against the stop 63 by the pressure in the chamber 46. The valve 4!! under these conditions moves from its seal and simultaneously the valve stem 66 is projected through the piston 62 into the chamber 46. Through a port 62' in the piston 62, the oil trapped in the piston is released to enable the valve and stem to move relatively to the piston 62.

The check valves 43a (Figs. 5 to 7) and 61 (Figs. 8 to 10) are provided to prevent surge reaction back to the chamber 31 through the passage in the valve stem. For example, when the temperature of the oil in the system is subnormal, and particularly, when it is relatively cold, the thermostat efifects opening of the port 55 in Figs. 5 to 7, and the port 10 in Figs. 8 to 10. Under such conditions, a sudden surge in the oil pressure in the chamber 23 may be sufflcient to cause the valve member 29 to be unseated so that the surge pressure will be transmitted through bypass to chamber and through the port 55 (Figs. 5 to 7) or port 10 (Figs. 8 to 10), and the ball valve 43a (Figs. 5 to 7) or 61 (Figs. 8 to 10) will prevent the surge pressure from being transmitted to the chamber 31 and into the warm-up chamber or muff.

To protect the entry port 66' a screen 14 may be provided on the valve member 40.

The valve units shown in Figs. 8 to 10 inclusive, although of modified construction have the functions of the valve units shown in Figs. 5 to '7 inclusive. In the temperature range of normal operation, the pressure in the chamber 46 is equalized with the pressure in the chamber 31 by bleed through the restricted opening 66', and the full pressure of the spring 64 is therefore effective to maintain the valve 45 closed, thus causing the oil to circulate through the cooler core. Below this range of normal operation, however, the bimetal coil will eflect the opening of the escape port 70, thus permitting the pressure in the chamber 46 to equalize with the pressure in the core outlet 2 I, and the higher pressure in the chamber 31 to overcome the resistance of the spring 64 and shift the valve and piston 62 to efiect opening of the valve 40. Under excessive pressure diflerential 0r surge conditions, even though the port 10 is closed and the chamber 46 under high pressure, the valve 40 may open as a result of the yielding of the spring 66, permitting the valve 40 to slide relative to the piston 62.

I claim as my invention:

1. An oil cooler comprising: a cooler core and a warm up bypass arranged in parallel with a common inlet and separate outlet and a main cooler outlet in communication with the core outlet and a port for establishing communication between the bypass outlet and said main cooler outlet; a valve unit including a valve head for closing said port and a tubular body, said valve head having a restricted aperture exposed to the fluid pressure in said port; means including said valve head and tubular body defining a fluid pressure chamber into which the fluid pressure from said port may be transferred through said aperture, whereby to apply said fluid pressure to said valve head in valve closing direction; a check valve for preventing back surge from said fluid pressure chamber to said port through said aperture; spring means for applying pressure to said valve head in valve closing direction chamber of said bypass" pressure so as 5 said valve to open undei sa-id' fluid pressure act ing against saidhadiapilot' valve closing said escape opening? responsive element adapted,- Wheri ture of the oil fiowing' to said-ma let is within a normal operating-r" said pilot valve element tescape opening-and permittin" build up insaid chambef'rid, 37V ture isbelow said 'nofma'lf opr'a said-pilot valve eiemen to 'p escape opening; permitting" the chamber to substantially edii ize sure at the core outlet, -and to overcome the 'pre's'su and permit a flvithrouh s 2. In" an oil cooler? with saidcore, said' co common inlet and separ therethr'ou'gli? a valve odap prevent flow througli tli'ehv the fullflow tO- ass tn H the-same; means'for-closi y temperature of fluid fio'wmg through cooler is withir'ia norm ti meanscomprisingsaid normal range," to'-"rlieve Said v Iv or fluid pressure in the valve'cIosin'""dire" 0 to permit thefluidpres'siuew' fig-a" valvein the opening directi' force of said medhahical mafis ailli ause Hie valve'to open. I 3. Control mechanism for having a heat transfi prising-5 a valve which flow'through theb'y'paiss I flow to pass through theporei said-v" subject to fluid pressu" against fiuid' pressure; 5

changer is within a ndilfiall' operas thermo-respons'i've ma' wmc perature of said fluid is b iows relieves said valve "of said in valve closing dire'cti'd fluid pressure to open th relief valve assi'jciatd vvit plying fluid pressf t" rection" so as tof-"bp'eii whens becomes excessive" and pe escape fromsai'dpre's'su open under said press re. 4. Control mechanism or having a heat traiis'fe v adaptedjwhen'the teniperat'urei of'tthe' oil nowr g and; "wheff said temperaturesbelow 'said p the ya-lvetclosing di motion: thei =respon vmeans openabiewyhon' same temperature is held aid n rmar range to dassto permit;the""fiuid pfessure acting.

r of 's';aiif mechanical-*mans and cau'se tfiva1ve o open} and'mldaded"pressure relleiivalv controlling saidpassafie means andopena-bre'under e'idessiveflui'd pr'ssure toipermit plfingmeansso as to "permit: the first mentioned valve to'operrirres ectiveofitemperaturen oil cooler comprising a cooler core" and af-warm' up :bv'pa'ss arranged I in parallel i witlil'i a;

common inlet and separate outlet" and=":a "malri3 ii fluid pressure iroinsaidi portmay'iie transrerr'd throng said? aperture? whereby to apply sa;id fiulde ressiire' :to'? 's'aid valve head iii-i the: valve? closing -direction a check waive 'for preventing. back surg tromisaid fiuid pres'surefchamberi to:

' said port througirsaidm perture ;?5 spring means forabplyihgmressiiie to"'s"ai'd= valve' hea'd in valve. closingdiredtion cooperatingwith-'saidffluidx pressur inmaintaining said. valve inits CIOsedpo'sltiomgsaid tubular-body having arifluidres cape opening for relieving? said chamber:.:of:; said" by pass: pressure so :as permitxsaid "valve to zbpenia under E'saidiflfluid pressure acting i: againstij said" head a" pilot valve 'meinb'eri for closing said? escape opening ;i- 0 a thermoresponsive element? to"sa.iil=niain'coolenoutlt is .witliinxanonnalfop; crating-range; to'remov's'a-id pilot valve elementtov'a "position closing-s escape oper'iing-" and poiinittiii'g thefpressui tdimildiub in"- said cha normal"operating-level? fio move 'said' pilot valve element tojii' positioii-"o eningsa e cape open: ing,- permittingitnef ressiifein sues anally-equalize: with cdfebl'itl ti and ciie bypa ii ss on; means, including a yielding mechanical device and said fluid pressure, urging the valve in the closing direction when the temperatureofthe fluid flowing through the heat exchanger is within its normal operating range; thermo-responsive means, openable when said temperature is below said normal range, for relieving the fluid pressure in the valve closing direction; and pressure relief means, opening under excessive fluid pressure, to permit the escape of excess fluid pressure urging the valve in the closing direction.

7. In control mechanism for heat exchangers having a heat transfer core and a bypass, comprising: a valve controlling said bypass, said valve being urged in opposite directions by fluid pressure in said bypass upstream thereof; yielding means urging the valve in the closing direction; temperature responsive means controlling the pressure urging the valve in the closing direction and relieving said pressure when the temperature of the fluid in the heat exchanger is below a normal predetermined value; and pressure responsive means for relieving the pressure urging the valve in the closing direction when the pressure tending to open the valve is a predetermined value. a

8. An oil cooler comprising a heat transfer core and a warm up outlet in parallel relation with a common inlet and separate outlet, said cooler having a main cooler outlet, a thermostat chamber interposed between said main cooler outlet and said core outlet, and a bypass port {or connecting said bypass outlet to said thermostat chamber; a valve including a valve head cooperable with said port to prevent flow through said bypass and cause the entire flow to pass through the core and a valve stem having a fluid transfer passage communicable with said bypass through a restricted aperture in said valve head; a piston slidable on said valve stem; stop means limiting outward movement of the piston on the stem; cylinder means cooperating with said valve stem and piston to define a fluid pressure chamber communicable with said bypass through said transfer passage so that said bypass pressure may be applied to said valve stem in valve closing direction, said valve head and restricted inlet being exposed to said bypass fluid pressure in valve opening direction, said valve stem having a fluid escape port adapted when opened to permit the pressure in said chamber to substantially equalize with core outlet pressure; sto means limiting outward movement of the piston in the cylinder; a spring urging the piston toward the flrst mentioned stop means; a spring urging the piston toward the second mentioned stop means; a pilot valve cooperable with said fluid escape port; and thermo-sensitive means disposed in said thermostat chamber, said thermo-sensitive element being operable to move said pilot valve element to a position closing said escape port when the temperature of the oil in said thermostat chamber is within a normal operating range, whereby to permit the pressure to build up in said fluid pressure chamber, and when said temperature is below said normal operating range, to open said escape port, Permit the pressure in said fluid pressure chamber to substantially equalize with core outlet pressure, and thereby permit said valve head to yield under the pressure thereagainst and the fluid in said bypass and permit flow through said bypass into said thermostat chamber and thence to said main cooler outlet.

9. In an oil cooler: a cooler core; a warm up bypass arranged in parallel to said core, said core and bypass having a common inlet and separate outlets; a main cooler outlet, including a thermostat chamber, in communication with the core outlet and a port for establishing communication between the bypass outlet and said main cooler outlet; a check valve for preventing reverse flow through the core outlet; a bypass valve, including a valve head cooperable with said port, for preventing flow through said bypass and routing said flow through said core, said valve including a tubular valve body providing a fluid transfer passage communicable with said bypass through a restricted inlet in said valve head; a check valve in said fluid transfer passage for preventing fluid flow toward said valve head; a piston slidable on the end of said bypass valve body opposite said valve head; a cylinder in said control housing in which said piston is slidably mounted, said cylinder and piston cooperating to deflne a fluid pressure chamber into which the bypass fluid pressure may be transferred through said passage and be applied to said valve in the bypass valve closing direction; a. spring under a compression between said cylinder and said piston for urging said bypass valve in the closing direction; a spring under compression between said valve head and said piston adapted normally to transmit valve closing pressure from said piston to said valve head but to yield under excess pressure against said valve head, permit ting said valve body to slide in said piston and said head to yield relative to said piston, said valve body having a fluid escape port through which the pressure in said fluid pressure chamber may substantially equalize with the pressure in said thermostat chamber; a pilot valve cooperating with said escape port; and a thermo-sensitive element in said thermostat chamber, connected at one end to said pilot valve and at its other end to said bypass valve, adapted, when the temperature Within said thermostat chamber is within a normal operating range, to move said pilot valve element to a position closing said escape port and permitting the pressure to build up in said pressure chamber and, when the temperature is below said normal operating range, to open said escape port so as to permit said valve head to yield under the pressure thereagainst and allow fluid to pass through said bypass.

10. Control mechanism for a heat exchanger having a heat transfer core and a bypass, comprising: a valve adapted when closed to prevent flow through the bypass so as to cause the full flow to pass through the core, said valve being subject to fluid pressure tending to open the same; means for closing said valve when the temperature of fluid flowing through said heat exchanger is Within a normal operating range, said means comprising means for applying yielding mechanical pressure and means for applying the aforesaid fluid pressure to the valve in valve closing direction; thermo-responsive means adapted when said temperature is below said normal range to relieve said valve of said fluid pressure in valve closing direction so as to permit the fluid pressure acting against said valve in opening direction to overcome the pressure of said mechanical means and cause the valve to open; and pressure relief means for relieving excess pressure on the valve in the valve closing direction upon a sudden increase of pressure against the valve in the opening direction.

11. In an oil cooler: a cooler core; means defining a warm up bypass arranged in parallel aeroso :13 with said core; said: coreandflbypass-having-a. common inlet and separateroutlet; a main cooler outlet in communicationzwith the coreoutlet, and v a port for. establishingcommunication between the bypassoutlet and. said main cooler outlet; means for controlling the flowsthrough'the core outlet and for preventing reverse. flow, therethrough; a valve adaptedLWhen closedto prevent flowthrough the bypass sons to causeithe full flow to passthrough-thecore, saidfvalve being subject to fluid pressure:tendingtowopen the same; means for closingsaid valverwhen the temperature of fluid flowing through said :oil'

cooler is-withina normaloperatingrange, said valve 'toopen and pressure relief meansfor -re'-- lieving excess pressure on the valve in the valve closing direction upon a sudden-increase of pressure-against the valve inthe openin'gdirection;

12.- Control mechanismior-a-heat exchanger, comprising: a housing"having aninlet, an outlet, a bypass inletand a" bypass-connecting said bypass inlet with said outlet; a valveadapted, when closed; to prevent flow through the bypass; said valve being urged in the 'openingdirection by' fluid pressure in the inlet side ofsaid bypass; means for applying yielding mechanical pres sure and means forapplying said fluid pressure in the valve closing direction; thermo-responsive means for relievingsaidvalve of the fluid pressure urging said valve in the closing direction when the temperature of'the fluid adjacent the housing outlet is below a predetermined temperature range so that fluid pressure. urging-said valve open may overcome, said yielding mechanical pressure and cause said valve to open and anexcess pressure relief means for relieving, the pressure of" fluid, urging thevalve' in thegclosin'g direction, when said pressure. r ses. excessively;

I3, A, valve mechanism, comprising; aavalve element adapted to control afluidflow. passage; avalvestem extending axially from said-ralve element; said stem having a restricted" passage therethrough; a piston mounted on said stem adjacent the end opposite said'valve element; a member having a cylindrical recess-in which said piston is slidable, the passage in said stem communicating. with said-cylindrical recess; yielding means urging the valve element away from said member; an outlet port for relieving fluid pressure in said recess; thermo-responsive means for controlling said port and opening same when the temperature thereof is below a predetermined value; and excess pressure relief means which allows relief of excess pressure in said recess upon a sudden rise in the pressure of said recess.

14. The invention defined by claim 13 wherein there is a check valve controlling the passage in said valve stem so as to permit a flow of fluid toward said recess and preventing the flow of fluid in the reverse direction.

15. Control mechanism for a heat exchanger, comprising: a housing having an inlet, an outlet, a bypass inlet and a bypass connecting said bypass inlet with said outlet; a valve adapted, when closed; to; prevent flow through-the bypass;:.saidr valve being urged: in :the..openingtxdirection by fluid pressure in.-.tbe. inletlend of said: bypass; means for applying yielding mechanical pressure in the valve closingdirection; meansforapply ing said'fluidpressureto. thezvalvein the, closing direction; thermo-iresponsive meansxfor reliev ing: saidv valve of the l fluid :pressure .urging said. valve in the closing direction when .the .te'mpera'e ture of fluid adjacent the housing-outlet is below. a predetermined temperature range so that-fluid pressure urging :said valve; open v may: overcome said yielding: mechanical II pressurexand effect opening: ofsaid valve; andan excess pressure: relief valveforrelieving: the pressure: of fluid urging the valvo in the :closing: direction when said pressure risesexcessively;

l6. A valve mechanism, comprising: aavalve' element adapted to control "a fluid passage; a valve stemv extending substantially axially from said element; apiston mounted on said stem' adjacent the end opposite said-valveel'ement; a member having a cylindrical recess inwhich said piston is slidable, said stem having"a-passagetherethrough in restricted communicationwith the front face-ot-said valveelement -andcommunicating with the cylindrical reeess yielding means urgingthe valve elementaway from said member; an outlet port for-relievingfluid pressure in-said recess; thermo-responsive means-{or controlling said port and openingsame when the temperature thereof is below a predetermined value; and- 'anexcess pressure --re1ief" valve for. relieving excess pressure in saidrecessa:

17. The invention deflnedby claimsld" wherein there-is-a check valvecontrolling" the passage through the valve stem, 'saidchech valve per mittingfluid flow through said passage from the end of the stem carrying thevalve element for preventing reverse flow through said passage-.-

l8. A valve mechanism; comprising-r a valve element adapted to controla fluid -passage;--a valve stem extending axially"from'said-element; apiston secured tosaid-stem adjacent the-end opposite said valve element; amember havinga cylindrical recess-in-whichsaid-piston is slidable, there being-a pressure chamberdefined; by the walls of-said-recess andsaidpiston; saidvalve stem having a passage therethrough from the end having the valve element, said-passage com municating with said chamber,--the end of said" passage adjacent the valve element" being re-' stricted; a spring urged check valve adjacent the restricted end of said passage-forpermitting a fluid *flow' towardsaidchamber but preventing a reverse flow through said-passage; a pressure relief port insaidstem-betweensaid check valveand piston; a port controlling valve operabl-y mounted on said stem; atemperature responsiveelement secured to said valve-element and to said port controlling valve for operating the latter; an excess pressure relief passage in said piston; an excess pressure relief valve controlling said passage and slidably mounted on said valve stem; and a spring disposed on said valve stem for urging the excess pressure relief valve in the closing direction.

19. Control mechanism for a heat exchanger, comprising: a housing having an inlet, an outlet, a bypass inlet and a bypass connecting said bypass inlet with said outlet; valve means for controlling fluid flow through the bypass, said valve means including a valve element urged in the opening direction by fluid pressure at the inlet end of said bypass; a valve stem extending substantially axially from said element; a piston slidably mounted on said stem adjacent the end thereof opposite said valve element; a member having a cylindrical recess in which said piston is slidable, the walls of said recess and said piston defining a pressure chamber, said valve stem having a passage therethrough connecting the front face of the valve element with said chamber; yielding means urging said piston outwardly relative to said recess; yielding means disposed between said piston and the valve element urging said piston and valve element away from each other; thermo-responsive means for relieving the pressure in said chamber when the temperature of fluid adjacent the housing outlet is below a predetermined temperature range; and an excess pressure relief port for relieving pressure in said chamber, said port being of restricted size and open at all times.

20. A valve mechanism, comprising: a valve element adapted to control a fluid passage; a valve stem extending substantially axially from said element; a piston slidably mounted on said stem adjacent the end thereof opposite said valve element; a member having a cylindrical recess in which said piston is slidable and cooperable to form a pressure chamber, said valve stem having a passage therethrough connecting the front face of said valve element with said chamber; yielding means urging the piston outwardly relative to said recess; yielding means reacting between said valve element and piston; an outlet port for relieving fluid pressure in said chamber; thermo-responsive means for controlling said port and opening same when the temperature thereof is below a predetermined value; and an excess pressure relief port for relieving excess pressure in said chamber, said port being open at all times.

21. The invention defined by claim 20, wherein the passage in said valve stem is controlled by a check valve permitting fluid flow in said passage toward said chamber and preventing reverse flow through said passage.

22. A valve mechanism, comprising: a valve element adapted to control a fluid passage; a I

valve stem extending substantially axially from said element; a piston mounted on said stem adiacent the end opposite said valve element; a member having a cylindrical recess in which said piston is slidable, the walls of said recess and said piston defining a pressure chamber, said stem having a passage therethrough connecting the front face of the valve element with said chamber; yielding means urging the valve element away from said member, said yielding means and the fluid pressure in said chamber being adapted to urge the valve element in the closing direction and pressure in said passage on the front face of said valve element being adapted to urge said element in the opening di- 16 rection; an outlet port for relieving the fluid pressure in said chamber; and thermo-responsive means controlling said port.

23. A valve mechanism, comprising: a valve element adapted to control a fluid flow passage; a valve stem extending axially from said valve element, said stem having a restricted passage therethrough; a piston mounted on said stem adjacent the end opposite said valve element; a member having a cylindrical recess in which said piston is slidable, the passage in said stem come municating with saidcylindrical recess; yielding means urging the valve element away from said member; an outlet port for relieving fluid pressure in said recess; thermo-responsive means for controlling said port and opening same when the temperature thereof is below a predeterminedvalue and excess pressure relief opening for relieving excess pressure in said recess.

24. A valve mechanism, comprising: a valve element adapted to control a fluid passage; a valve stem extending substantially axially from said element; a piston slidably mounted on said stem adjacent the end thereof opposite said valve element; a member having a cylindrical recess in which said piston is slidable and cooperable to form a pressure chamber, said valve stem having a passage therethrough connecting the front face of said valve element with said chamber; yielding means urging the piston outwardly relative to said recess; yielding means reacting between said valve element and piston; an outlet port for relieving fluid pressure in said chamber; thermo-responsive means for controlling said port and opening same when the temperature thereof is below a predetermined value; a restricted excess pressure relief port for relieving excess pressure in said chamber, said port being open at all times.

RAYMOND W. JENSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

